1. Field of the Invention
The present invention relates to data transmission in a Digital Living Network Alliance (DLNA) network environment and, more particularly, to a system and method for data transmission in a DLNA network environment wherein created content is classified by category and the classified content are converted into common-format contents and can be provided as a single unified file.
2. Description of the Related Art
In recent years, a growing number of audio/video (AV) content such as songs and videos have been exchanged through Internet Protocol (IP) networks. For example, viewing television programs or listening to songs through the Internet is now regarded as a matter of course. Home users tend to exchange AV contents through networks. Users have a growing interest in home networks, which connect various home AV appliances together for easy enjoyment of AV contents. To achieve this, various automation mechanisms are necessary. Connecting home appliances to LAN interfaces or providing wireless LAN features to the home appliances is not enough. The home appliances must be aware of the presence of other appliances, discover necessary content and exchange desired contents, through networks.
Various middleware-related standards such as UPnP, HaVi, Jini, VESA and DLNA are employed to discover other appliances on networks, and find and exchange desired content through the networks.
In particular, DLNA focuses on sharing of all types of contents provided by various appliances such as a TV, VCR, digital camera and audio system. Content sharing requires interoperability between appliances. A network in the home connecting an Internet network (PC and printer), mobile network (PDA, mobile phone and notebook) and home appliance network (TV, audio system and DVD player) together should conform to a standardized interoperability framework and satisfy operability requirements for products.
DLNA aims to enable consumers to acquire digital media contents (for example, photographs, songs and videos) from mobile devices or personal devices such as PCs, and to distribute and manage them. That is, DLNA aims to enable a consumer to conveniently enjoy media content irrespective of the locations and appliances in the home.
To achieve this, a DLNA system is based on Universal Plug and Play (UPnP) technology, and can be a wired/wireless network system including Digital Media Server (DMS) devices, Digital Media Player (DMP) devices, Digital Media Controller (DMC) devices, and Digital Media Renderer (DMR) devices.
The DMS devices, DMP devices, and DMC devices include mobile DMS (M-DMS) devices, mobile DMP (M-DMP) devices, and mobile (M-DMC) devices, respectively. M-DMS, M-DMP and M-DMC devices can be connected directly or through access points (AP) to the DLNA system. A Mobile Network Connectivity Function (M-NCF) device is present at an AP as an intermediate node connecting an M-DMS device and M-DMP device together.
The DLNA system can employ a wired network (IEEE 802.3) or wireless network (IEEE 802.11) to compose a home network. DMS, DMP and DMR devices on the home network are interconnected through the wired network or wireless network. Digital devices on the home network can transmit data such as images and voices through the IEEE 1394 interface.
For standardization of DLNA systems, the DLNA Networked Device Interoperability Guidelines define the Home Network Device category including DMS devices, DMP devices, DMC devices and DMR devices, and provide conditions for interoperability between DMS, DMP, DMC and DMR devices.
A DMS device, corresponding to a media server device (MSD) in the UPnP AV model, has functions to access and store digital media content and provide them to DMR devices. The DMS device is to permit a control point (CP) acting as a user interface application to discover digital media content in the DMS device so that users of a DLNA network can display or distribute the content. As an example of interaction between a DMS device and DMR device in digital broadcast reception, the DMS device receives and stores broadcast programs, and then sends a requested broadcast program to the DMR device, in response to a request from the DMR device. The DMR device then reproduces the received broadcast program. The DMP device is a DMR device including a UPnP CP, and acts as a Media Renderer Device (MRD) and Media Renderer Control Point (MRCP) for selecting and controlling media contents and playing back selected contents. Media contents provided through the DMS device to the DMP device and DMR device have been received from various sources in various ways.
As described above, media content provided through a DMS device have various data formats. To play back a media content of a particular format, a home appliance has to install a required application. If the required application cannot be installed, the home appliance cannot play back the media content.
The content providing service of the DMS device is limited to reception and reproduction of media content files selected by the CP. Hence, it is necessary to provide an extended service that enables the CP to discover and access media content files in various and convenient manners.